Urine

Assalamu Alaykum Mufti , i recently came across one site www.zikr.co.uk and the Hadhrat name for the site is Muhammad Sardar Ahmad Naqshbandi (d.b) Firstly is he from the Ulama Haq ? Secondly the following things were found on his site and I had a doubt if these incidents etc . were authentic so could you please clarify :

A.)
Cleansing With Water
‘Aisha (may Allah be pleased with her) narrates that, ‘The Messenger of Allah (may Allah bless him and grant him peace) went to answer the call of nature, ‘Umar (may Allah be pleased with him) brought some water. The Messenger of Allah (may Allah bless him and grant him peace) said, ‘What is this” He replied, ‘Water for cleansing (Istinja).’ The Messenger of Allah (may Allah bless him and grant him peace) said, ‘It has not been made necessary (Wajib) upon me after urinating to cleanse myself with water.”

B.)
In the books of Hanafi Fiqh (Jurisprudence) it states it is Makrooh-e-Tehrimi to hold urine/wind or the need to go to the toilet. One should relieve themselves first as the Salaah will have to be repeated. It is said that holding urine is harmful for the body, just as everything around a stream is destroyed if it is held up.

C.)
No More Stomach Ache
. A woman accidentally drank some of the Messenger of Allah’s (may Allah bless him and grant him peace) urine. Then the Messenger of Allah (may Allah bless him and grant him peace) told her, ‘You will never complain of a stomach ache.’
Ibn Jurayj (may Allah be pleased with him) narrates that, the name of this woman was Baraka, but they disagree about her lineage. Some say it was Umme Ayman, who would serve the Messenger of Allah (may Allah bless him and grant him peace). She said, ‘The Messenger of Allah (may Allah bless him and grant him peace) has a wooden cup which he placed under his bed, in which he would urinate during the night. One night he urinated in it and when he examined it in the morning, there was nothing in it.’ He asked Baraka about that. She said, ‘I got up and felt thirsty and drank it without knowing.’

D.)
And on another website i think it was islamqa or something the mufti gave an answer that said it permissible to urinate standing as long as it doesnt splash , is it not compulsory for us to sit ?